Electric power is a convenient and steady energy source for modern households. Due to electricity is invisible to human eyes, electric shock or leakage resulted from users' negligence could cause hazards to people' life or property damage. This concern is especially serious for houses which have babies or small children. Hence safety use of electric power is an important issue that needs more attention. Most houses have power supply receptacles installed on lower locations of the walls. Children often have a great curiosity and try to insert metallic articles into the receptacles that are electric power-enabled. It is a dangerous action that has to be guarded against constantly.
To prevent the risky situation mentioned above from happening, some techniques have been proposed. For instance, R.O.C. patent Nos. M312819, M249294 and 337384 disclose a protection means for safety receptacles with a safety gate to prevent electric shock. M312819 and M249294 have a detent plate located between receptacle slots and electrodes. The detent plate is pushed by a spring in regular conditions and located beneath the slots. When a plug is inserted into the slots the detent plate is moved so that the plug prongs and the receptacle electrodes can be connected. Although in M312819 and M249294 the detent plate blocks the slots of the receptacle, when in use the detent plate can be moved away by inserting one slot forcefully to expose another slot. Hence protection effect is compromised.
Patent No. 337384 provides a universal safety receptacle and plug. The receptacle has a control seat and a safety detent plate that are interposed by a spring which provides a push force so that the safety detent plate is maintained at a lower side of the slots of the receptacle in regular conditions. The safety detent plate has an inclined top surface. When the plug is inserted into the slots the detent plate is pushed and moved. The safety detent plate also has a flange at the top surface and the control seat has a notch on the top surface thereof corresponding to the flange. In the event that the safety detent plate is subject to a force from one side or unevenly, and results in a biased movement to the left side or right side, the flange is moved upwards to latch the notch so that detent plate is hindered from moving rearwards. While such a latch structure in Patent No. 337384 can prevent the safety detent plate from being moved away by an one side or uneven force, the latch relationship between the flange and notch cannot withstand too much of applying force, or movement of the safety detent plate still could happen and result in compromising of safety protection. Therefore, Patent No. 337384 can not provide safe measures efficiently.